PBS/Logo Variations
The MacNeil/Lehrer Report (1977): The April 19, 1977 episode has the 1971 PBS logo superimposed on top of the studio where the show was filmed, which cuts out by the time the "S" is present.
We Interrupt This Week (1978): The regular music was replaced by a male choir singing very loudly, "Happy birthday to you!!". This audio was taken from the episode itself and used as a liner for this variant. The source of the audio from this episode was when the host played a video of the male choir singing the song to a woman (the birthday recipient). If one listens carefully at the beginning of this variant, the normal music can be faintly heard underneath.
Southbound (Mouth Music) (1981): The 1971 logo is a capella.
Square One TV (premiere) (1987): The 1984 PBS logo, when completed, duplicates several times creating a trail effect. This is accompanied with a sound clip from the episode: "and on, and on, and on".
Christmas with the Tabernacle Choir (2019, 2020 rebroadcast): The 2019 closing logo is abbreviated, starting with the P-head already zoomed out, and the music has some electronic backing.
